Countercurrent extraction process and apparatus



M. BoNoTTo 2,614,911

COUNTERCURRENT EXTRACTICN PROCESS AND APPARATUS Oct. 2l, 1952 2 SHEETS-SHEET 1 Filed May 7, 1947 FLAKES 8 Sow N-r 1N m m u M w u m ,...r w ...w u 2 Cw w ,LYO T0.. 9 E M an (Il M VE m m 1 .l m ma. mm z, s w w w ww M U E UW 9u .H I M W GV on 2 D. .I D m M o Il 5 N m 7 D.. 1 l: l P 5 3 w 13% Y A 2 S i B D N i n0 @n m M '3 MNA im. A m wm u mn o w14- mm T T m. o M w N r m P Mov l M., HS l l l N w wm m 5 Mw Zwe 2 w o 3 E 37. 2 9 ao E mm N M 2 xr WhmNww/w 3 3 1 2 M S A I u M. m w mm ma m m 6 H M mm M W MR E m am 1.7M A 2. M7 u uP n P 15m a Am m 6 N In m m H e, Mm |v m w .1.. WU /N 1.... Y N E 6 AE R U n O 7 F 1 W5 M 2 c m o mnu.. 1 E W A 1 7 7. m. l, w 2 M .l L w TU c 1 0 m..

Patented Oct. 21, 1952 i ANDfAPPARA'BUS ""Michele "Bonotto, Princeton, N. J.

fAmlicationlMay 7,1 1947,ffSerialiNoWIGZ i i4 claims. (ci,V zes-310) l `1 This invention relates Vto `improvements zin process and 1 apparatus `for `,the continuous i counter-current `extraction of buoyantimaterials fand for `the continuous filtering and. settling -of miscellaembodyingbuoyantflnes.

In earlier patents,:I.have-shown and `described process and apparatus for `,thecounter-current extraction of oil fromoilbearing process: materials having greater `weight-,per .volume than `the solvent employed so Yas -to sink thereiny'also `in myPatent #25273;557, dated February ,17, `1942;,1 have ,disclosedfa continuous counter-current .extraction apparatus adapted ,to f extract `oil from similar V,sinking material fed thereto Vin naked condition, andl have passedsuchflaked process material ,through anelongated material-ffeeding conveyorfconduit into -which ,miscella 1.from `.the extractorf is fed iso that lthe said, conveyor-conduit embodies a. filter i section-,and thej .naked material being conveyed through saidico'nduit isutilized as a yltering medium for the miscella. The process material being conveyed is thus ,loaded and has `its, interstices `iilled with :fines of the same rmaterial, ,and #is .thereafter fedrinto rand passed through Athe .extraction v.apparatus .1in a conventionalmanner.

M'In the ,apparatus and ,process ,.of, said .Patent No.. 2,273,557, the, filter section -is ,provided ,with perforations`` or screens vinthe` `.wallsof `the con-I duits through which the filtered. miscella ,or Ifiltrate `passes `toaedisoharge outlet'. With `certain `types .oftmateraL .thejscreens of rmYsaid patent the processjmaterialkn said conduitfnesfinlsaid r to provide rprocessrri nd apparatus fin which process materia-ls ,ionamin-either solid7 ,1F-1 ,aleedrlorf granulate dzcondi-tioniare e1?l lowerfspeciilc gravity than lthetsolventutilized;` and ffloat therein may be `sumeoted to'continuous counter-currentextraction preferably,intanextraction.colixmm havingleiiciency characteristics :similar 'ato .those l of my said ,earlier l patents; VLto .utilize 1a a feed-iconveynr ::;conduit with saefeedingfload ,therein as: a

`filter tier :miscella zfrom :the t extractor; :to :t cause buoyant fines nin :'miscella :of "1 such ya, :relatively heavy liquid :solvent tto `be subjected nto,V azxnes floating `and :separating :action `rand Lduring the conveyance tof the process :material 1 toffthe :extractor; Lto `cause such."lneszitoubetloaded uon ,f and carried :with saidvprocess nnlaterial .into the extractor. i whereby'thevprocess. material willc'be en rched with such floated buoyant xinesefrom.

miscellaiproducedintthe extractor.` i

sA'notherob'j ect dill-my invention! is ito improve and adapt" the-extraction column kmore 1 particularly `shown and described finfmyfearlierfPatent throughthe' bottomthereof," anditofeausei-n 4said column anormal upward floatingeofbuoyant movement `thereoithrough ,av-heavier, solvent fed into. the upper portion-.of saidextractionvcolumn above or atfsaid' liquidglevel.aridhaving` an'ormal downward "flow ofjmoveinent "through `andin i counter,-curren't4 with,saidbuoyantproeess mate- 'Another objcaroffgtfriy ,invention isn tof erotico in ,an .extraction @column form .use with `'solvent-` buoyant .materials of thefgcharacter `specified means` for subdividing the, extraction ,column into a series aol )sections by ;:pressure'-,eqiializing'` `inartitions .having openings, preferahlypdisposed radially of ,thelaxisl oi the column '.andllocatedout of r.registration l.with t each `.othen also providing means for rotating said partitions to permit kan upward floatingmoyement through sucherevolv' ing openings .,ofgmaterial and .the Acoun-ter:cur-L rent movement` of 1A,the [heavier .solvent throh the varoussectionsef said.extractionsicoluinnmso as to 4 i.produce greatly increased rdistribji'ition ,i of the solventl eicient .extractionllof the il from suchmaterial;

Another object of my invention is to support in the upper portion of each of such sections below the rotating pressure-equalizing partitions, one or more stationary radially-extending scraper arms which provide positive stops against revolving movement of the process material with the partitions. o

Another object of my invention is to provide at the upper end of an extraction column mechanism for compressing and discharging extracted material or cake, in combination with conduit means connected with the bottom of the extractor and extending above the liquid level for discharging miscella from said bottom of said column. lAnother object of my invention is to connect with the bottom portion of a feed conduit of the type hereinabove specified, the top settling portion of a buoyancy settling tank, to pass and discharge the miscella product of said extraction column through said settling tank and to load settledbuoyant fines from the miscella into the process material being fed to the extraction column,-. thus enrichi-ng such material during its conveying movement to thev extraction column.

Another object of my' invention is to `provide a construction :of the type specified in which a single, continuous conveyor conduit may be. utilized as a feed' conveyor, asoaking section, a'lter andfeed lsection for the extraction column and also a discharge.` section. therefor.

Still another object ofmy-invention is torenable the efficient extraction of process materials that become buoyant when thinly or nely comminuted, iiaked or granulated and also to enable the use of solvents of irelativelygreater weight per givjen volume thanv theflaked comminuted Aor granulated process material.

embodying my extraction column combined with feed and discharge mechanism for'process materiatand solventi#K l Fig. 2 is a section ontheline 2,-2 of Fig. l looking in the direc'tion'o'f the arrows;

Fig. Y3"is asect'ion ,on the line 3-3 VOf Fig'.r 1 looking in'thefdirectionof the arrows; v

fligfi 'isa fragmentaryillustrative view similar to Fig. 1 of a -modified form of my invention inwhich a drag-chain-conveyor is utilized' as thfmaterial-dischargemechanism;

Fi'gf isa section'on the'line 5.-5 of Figgi looking iny the directionfof the arrows; j

Fig..6`is an illustrativefview, partly in section and partly'i'n side elevation, of a modified form of apparatus ini which a V.single-drag-chain convey'or is utilized both asfa feed mechanism, soaking section;` filtering. section and discharge mechanism; i A, L o Fig. 7 is asection fon t e vline 1 -'i of Fig.l 6

lookingin the direction of the arrows; l ",AFigj. 8 isa `fragmentary View showing faform of apparatus. modiiedinrelation to Fig. 6 to omit the drag-chain' conveyor asu'the4 materialdischarge mechanismandto 'substitute'therefor a screw-conveyor discharge;

Figl 9 is a section on the line 9 9 of Fig. 8 looking in the direction of the arrows;

Fig. 1U is a section on the lines ifi-l0 of Figs. l, 4, 6 and 8 looking in the direction of the arrows; and

Fig. l1 is a section on lines lI-Il of Figs.

ysame with relatively heavy solvent fed into said column at the top portion thereof and thor- 2 oughly distributed therethrough by subdividing the column into pressure-equalizing sections lseparated by rotating partitions having radially-extending openings, and preferably providing'beneath such rotating partitions stationary or fixed scraper arms adapted to prevent rotation of the material with said' rotating partitions, and thus to provide for a highly efficient extraction of such solvent-buoyant material.

In the preferred embodiment of my invention I further improve the process of counter-current oil extraction lof such buoyant or floating materials by providing for a clariiication of miscella from an extraction column for such buoyant material in a continuous operation by first percolating and filtering said miscella in counter-current through and with a conveyed or moving column of flaked process material in said feed conduit to remove part of the fines therefrom; secondarily, to subject such miscella to a iloating separation'of the fines therefrom by passing and discharging or decanting such filtered miscella through a settling tank connected to the bottom portion of said feed-conduit to remove floating nes therefrom, and in the same operation to automatically introduce into the process material duringV conveying movement thereof the floating lines separated out in the floating separation operation; thus loading said buoyant process lmaterial with fines, first, in the percolating and iiltering operation and then in the addition ,thereto of settled fines, and, lastly, feeding said nesenrichedfprocess material of said buoyant type to an oil extraction operation in an extractor especially adapted .for such buoyant material. I preferably accomplish these results by acounter-current percolating and lteringmovement of the miscella product resulting from an extraction. operation in thev extractor through solid process material during a conveying and feeding movement thereofby a feed-conveyor conduit to theextractor, passing the ltered miscella through Aa nnes-iioating .and separation'tank connected` With the bottom of said feedconveyo'r conduit and discharging or decantfingthe saidlteredmiscella*through said tank; t o

I also preferably provide, in.- my feedconveyor conduit for an initialsoakingof the process materialv inthe miscella product of the extractor;

Referring now to these drawings, vvhiclril'lus-l trate a preferred embodiment of mechanical apparatus for carrying out my invention, yl indicates a`Y vertically disposed extraction column Vhaving -atgits, upper end a solvent inlet conduit Zand providedat its lower -endfwithan-inlet for processV material 'and also having ymounted 4at its upperend in communica-tion with the extractor managen rof the process lmaterial, so asfto cause-"the conduit `""4 i fandr *ther extraction column`1'to""be 'liquid .fiand `"vaporftghtr 1 j VLThej *lo`o`ttom-inletifendl ofthef-col-umn 'connected *thereto an Lendless drag-'chain conveyo'ri lhav-ingean outlet f portionifextendingdia- `metrically across i the bottom of i thefextraction =`clumn 'Iyas-` more particularly fshowniin Fig." ,ifa Lbodylnortioniextending ALiipw'aifdl'y-la ``suitablfei isi ltarieeibove me uqu-idlifevi inane: extractor-:anu "fisprovidedatitsi-upperiendwith-arr:mieu-section "t which.' asshoWm-isco'nnected a'ltee'd opperffQ. Said'drag-chain--conveyoricomprisesllegsa-lb separatedA `by a Apartition f" limandI 1the continuous mchairrtherein turnsagi'lthe;*lowerl endi ofthe-conlveyorecondu'itabout af suitable pulley? Ii-f aridwexl tends upwardlyr as aforesaid; afsuitable distance i above "the"l liquid -lev'el ai/'hereV `said chain f again turnsabolita-suitablepulley 8. *Thelinlet hopper *9"*1forth'e"iecding of` "naked I process "material-" is *preferablyconnected-i to Uthelegfflthef partition 'through the openingiini the partition Bciandlenter i. 2

the downwardlyfmoving Ilegflii, any iiakes which may be `engaged"a1f1d"carried by the upwardlymoving portion of thedrag chain conveyor will finally reach jthedownwardly moving portion or .leg and.in.operation,.the.leg.or conduit 6e ,will` be continuously full of process material.

Intermediate the conduit inlet'S for process material-` andthe column -inlet IIL-the full leg 6 is connected to the upper end IIa of a buoyancy wsettling-tank.I I and the extraction liqufidimiscella :with k itsdoa'd of oil will, waiter; rits" travelzthrough ltlie extractorrpassinto andsthrough affilterzsection 6? between the miscella outlet of the column and the fines-floating and` separation tank II and will then pass through the decanting or discharge pipe or conduit I2 to a position I2a extending above the liquid level to permit a suitable discharge or decanting thereof.

In Figs. 4 and 5 I have shown a modified form of apparatus of the general type illustrated in Figs. 1 to 3. In thisconstruction the extraction tank, inlet hopper for naked process material, buoyancy settling tank are in all respects similar to that shown in Fig. 1 but instead of the discharge-screw conduit 4 shown in Fig. 1, I provide a discharge mechanism comprising a doublelegged` drag-chain conveyor I3 having legs I3-I 3b connected, as more particularly shown in Fig. 5, with the top of the extraction tank I and extending below the liquid-level in the columnso that the floating process material rising in the liquid will pass upwardly into the leg |31. Movement of the drag-chain will then carry the process material from the extractor upwardly vout of and above the liquid and the conduit may have sufficient length to permit a draining for a suitable distance prior to connection with a discharge hopper I4 through which the process material is fed to a dischargescrew-conveyor I5, which is preferably provided also lwithlafl compressing for squeezingasection similar to IIa and a valve 5 so that such at rial willrbe dischargedlas .extracted material calzfeazfform. i 'Infall otherurespects the `1embodimentrshown in *FlgsA/i and `15 bis similar Jtothat: hereinabovei describedLinlrelationitorlFigsJlftoiS.-n: i i

nfFig. fin inventionlin which avsinglemontinuousEdragciiair'i'conveyorll l-zzisfutilizedftofeedfanddischarge :conveyor:pneterablycomprses: in :loner-Singlepartfduit; La, feedxsection I ,la :soaking `section ila rfines.-adding`4 section :I 3, :.atiilter sectionf'20 'i terial-,and-miscella.v receivingisection:l 2 `ifi-lied ibut rrnaterialf` emptylleg; 12 2 s and` .a processrmfaterial dischargeesection :r2.3 `recitendirrgg` .das iIslfioyvn,fsecaritially..Ltlrrou-ghiithepupperilpoitionzof itheiextractioznrtank."Iloto.receivezbuoyantiiprocess @materialfand itc convey: thezfsame` .torasidischarge section-i124 Swhicliuis :connectedxz-withacdischarge .fliopper 1. which in @turn his :ccnnectediiviith :.a screw-conveyor conduit 26 similarn'to'ithexidischarge; conduits hereinabove speciiiedawhichdisf charge the i? process J :material: in rcakefsiorm'-, flfAs .Y `sshown,'.atsolventfinlettconduitfluis;conrzlectedl at -the.iupperiendofithexcolumrnI'.` ndxithefsolvelntiis `pledaarrddis'tributed.throughthexcolumnlfilleli:with process materialfasi: hereinaboveispeciiied. frfIhis .liquid withtiitsloadafof. oil. andznes;lrthenccalled -miscellag1passes:into-zand throughxalneseiioating ndcseparationxtanlmmhich isLconnected tothe ibottom-zportion .of theuconduitnl6l.ati the fines- Waddinglsectionr lrsolthat .theL .buoyantiiines inithe .zmiscellaffrom thenextractorril will beisubjected oto.; arsettling factionliin theisettling rtan Zai-and nvfvilllzbe addedito1therprocessl.smaterialiibeingiied j -tofthef extractor, Iriandl'the imiscella ith-us-I clarified twill* `be.co1'id-ucte"d1` Atbycconduit 2li-129eV ntoa l.posivtionP-(l abovelltlielliquid'lleveland-"connectedl `toria suitablemiscellafoutlet 30e." I l if i i un rig;` stimare shown-another'modmedtfrm :otmy-1finventionin which Vaj-*lowfer portionofvthe Conduit) I15,"extract'ion colulrnnf Iybuoyancyrstfiltling' ta 28=and all-otherlowerfjparts of theidevice in--lall respects i similar to" 'thatshownf 'in `ig. `bifitthecor1di`ii-t-l 6 Lisjat its upper' enel' fentirely unconnected from jtheextraction jcolumn and instead of the receiving and discharge sections 23 and 24 I have provided an independent screw conveyor mechanism 3l which is in all respects similar to the screw conveyor mechanism 4 hereinabove described in relation to Fig. 1.

In each of the several embodiments of my invention shown, the extractor is provided with a series of rotatably-mounted pressure-equalizing partitions 32 which, as shown, are mounted on and rotated by an axial shaft 33 suitably .supported in the column and rotated through bevel gear 35 connected with bevel gear 35a iixed on. and driven by a shaft 36 from any suitable source of power not shown. The equalizing partitions 32 are each provided with a radially-extending aperture 323L and the openings or apertures 32 in these partitions are arranged in positions out of alignment with each other (see Fig. 10) so that solvent passing therethrough will be distributed into process material contained within and filling the various sections 31 between the partitions or plates 32. It is desirable to prevent the process material from turning with the rotating partitions or plates 32 and to prevent this rotation I mount in the upper part of each section 31 a pair of diametrically arranged scraper blades 38, which, in the embodiment shown, has a scraping m6Ifhave:illustratedvanenrbodimentafof A memoir 1. A process for the extraction of buoyant solid material in which a solid process material having a lower specific gravity than the solvent utilized is continuously passed through an extraction unit, a solvent having a higher specific .gravity than the process material is fed and conl tinuously passed in counter-current, to the movement of said solid material, and liquidmiscella is "produced, which consists in conducting said miscella to move continuously in counter-current withithe movement of said buoyant solid material toward and to the miscella outlet, forming during such conduction a pool of said liquid miscella, discharging said miscella through said pool, conveying the solid material across said pool of said miscella to cause a floating out of rines from said miscella and then conveying said solid material loaded with nes from the miscella to said extraction unit. v

2. A process vfor the extraction of buoyant solid material in which a solid process material having a lower specic gravity than the solventV utilized is continuously passed through anv extraction unit, a, solvent having a higher specic gravity than the. process material is fed and rcontinuously passed in counter-current to the movement of said solid material, and liquid miscella, is produced, which consists in conducting said miscella continuously in counter-current with the movement of said buoyant solid material toward and to the miscella outlet, forming from said continuously moving and conducted liquid miscella a pool, discharging said miscella through said pool, conveying said solid material in a path through said moving and conducted miscella to percolate the said miscella through said solid material and to add fines from said miscella thereto, and also moving said solid process material across said pool of said miscella to cause the floating out of fines from said miscella and theadding of such iines to said solid process material and thereafter conveying said solid material so loaded with nes from the miscella to said extraction unit.

3. Apparatus for vthe extraction of buoyant materials comprising an extraction unit provided at its lower end with a feeding inlet for process material having a lower specific gravity than the solvent utilized and at its upper end having means for discharging said material.. anA inlet conduit for liquid solvent of higher specific gravity than said process material havinga connection with said unit at the upper end thereof, a process material-feeding and miscella-discharge conduit having at its lower end a connectiony to the lower end of said extraction unit, said conduit being provided with a body portion extending outside said unit in an upwardly direction relatively thereto and having its opposite end projecting above the top of theA extraction unit, a feed hopper connected with said upwardlyextending material-feeding and miscella-discharge conduit at a position adjacent to the upper end andabove the top of said extraction unit, and conveyor means insaid upwardly-extending material-feeding and miscella-discharge conduit which extends and has an upper terminal above said feed hopper and a lower terminal extending below the connection of said upwardly-extending material-feeding and miscella-discharge conduit with said extraction unit.

4. Apparatus for the extraction of buoyant materials as claimed in claim 3 in which a buoyancy fines-separating tank has its upper end open and connected with the lower side of said material-feeding and miscella-discharge conduit at a position intermediate the feed hopper-and the bottom of the extraction unit, and conducting means connected with the bottom of said settling tank for discharging miscella therefrom.

:MICHELE BONOTTO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Bonotto Dec. 19, 1939 

1. A PROCESS FOR THE EXTRACTION OF BUOYANT SOLID MATERIAL IN WHICH A SOLID PROCESS MATERIAL HAVING A LOWER SPECIFIC GRAVITY THAN THE SOLVENT UTILIZED IS CONTINUOUSLY PASSED THROUGH AN EXTRACTION UNIT, A SOLVENT HAVING A HIGHER SPECIFIC GRAVITY THAN THE PROCESS MATERIAL IS FED AND CONTINUOUSLY PASSED IN COUNTER-CURRENT, TO THE MOVEMENT OF SAID SOLID MATERIAL, AND LIQUID MISCELLA IS PRODUCED, WHICH CONSISTS IN CONDUCTING SAID MISCELLA TO MOVE CONTINUOUSLY IN COUNTER-CURRENT WITH THE MOVEMENT OF SAID BUOYANT SOLID MATERIAL TOWARD AND TO THE MISCELLA OUTLET, FORMING DURING SUCH CONDUCTION A POOL OF SAID LIQUID MISCELLA, DISCHARGING SAID MISCELLA THROUGH SAID POOL, CONVEYING THE SOLID MATERIAL ACROSS SAID POOL OF SAID MISCELLA TO CAUSE A FLOATING OUT OF FINES FROM SAID MISCELLA AND THEN CONVEYING SAID SOLID MATERIAL LOADED WITH FINES FROM THE MISCELLA TO SAID EXTRACTION UNIT. 